A Radio Frequency (RF) tag transmits an RF signal at a specific frequency in response to receiving an excitation signal. The RF signal often identifies a product code. An RF receiver receives the RF signal and processes the product code to display associated product information. The RF receiver may also transmit the excitation signal.
Bar codes encode various types of information, such as bar codes. Some wireless telephones with cameras scan and process these bar codes. For example, a camera-equipped wireless telephone may scan and process a bar code to download information from a web site indicated by the bar code.